視覚障害を初発症状とするCreutzfeldt-Jakob病の1例

A case of Creutzfeldt-Jakob disease with impairment of vision as the initial manifestation

要約　目的：視覚障害を初発症状としたCreutzfeldt-Jakob病の報告。症例：61歳男性が数週前からの両眼の視力障害で受診した。7年前から糖尿病があり，9か月前に胃癌の内視鏡手術を受けた。輸血歴はなかった。所見：矯正視力は両眼とも0.15で，右眼に軽度の糖尿病網膜症があった。視野検査で左同名半盲があり，網膜電図（ERG）と蛍光眼底造影に異常所見はなかった。その後ミオクローヌスが生じ，21日後に会話困難，36日後に無動性無言となった。頭部の磁気共鳴画像検査（MRI）と単一光子放射断層撮影（SPECT）の所見からCreutzfeldt-Jakob病と診断した。結論：Creutzfeldt-Jakob病では，急激な視力障害と視野異常を初発症状とすることがある。

Abstract.　Purpose：To report a case of Creutzfeldt-Jakob disease with impaired vision as the initial symptom. Case：A 61-year-old male presented with bilateral impairment of vision since few weeks before. He had been treated for diabetes mellitus for 7 years. He had received endoscopic surgery for gastric carcinoma 9 months before. He had no history of major surgery or blood transfusions. Findings：His corrected visual acuity was 0.15 in either eye. The right eye showed mild diabetic retinopathy. Perimetry showed left homonymous hemianopia. Electroretinogram（ERG）and fluorescein angiography showed normal findings. He showed myoclonus later followed by difficulty in conversation 21 days later and akinetic mutism 36 days later. He was diagnosed with Creutzfeldt-Jakob disease based on findings by clinical course,magnetic resonance imaging（MRI）and single-photon emission computed tomography（SPECT）. Conclusion：This case illustrates that impairment of vision may be the initial manifestation of Creutzfeldt-Jakob disease.